Prevent system WebCore.framework from not working due to collisions with...

webkit/config.h.in

 /*
  * Copyright (C) 2004, 2005, 2006 Apple Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 109 matching lines @@
 #include <stdio.h>
 #include <snprintf.h>
 #include <limits.h>
 #include <wtf/MathExtras.h>
 #endif
 
 #if PLATFORM(CHROMIUM)
 
 #define WTF_USE_GOOGLEURL 1
 
-#if !PLATFORM(DARWIN)
+#if PLATFORM(DARWIN)
+
+// Chromium's version of WebCore includes the following Objective-C classes.
+// The system-provided WebCore framework may also provide these classes.
+// Because of the nature of Objective-C binding (dynamically at runtime),
+// it's possible for the Chromium-provided versions to interfere with the
+// system-provided versions.  This may happen when a system framework attempts
+// to use WebCore.framework, such as when converting an HTML-flavored string
+// to an NSAttributedString.  The solution is to force Objective-C class names
+// that would conflict to use alternate names.
+//
+// TODO(mark): This list will hopefully shrink but may also grow.  Periodically
+// run "nm libwebcore.a | grep -E '[atsATS] ([+-]\[|\.objc_class_name)'" and
+// make sure that everything listed there has the alternate ChromiumWebCoreObjC
+// name, and that nothing extraneous is listed here.  If all Objective-C can
+// be eliminated from Chromium's WebCore library, these defines should be
+// removed entirely.
+
+#define ScrollbarPrefsObserver \
+        ChromiumWebCoreObjCScrollbarPrefsObserver
+#define WebCoreControlTintObserver \
+        ChromiumWebCoreObjCWebCoreControlTintObserver
+#define WebCoreRenderThemeNotificationObserver \
+        ChromiumWebCoreObjCWebCoreRenderThemeNotificationObserver
+#define WebFontCache \
+        ChromiumWebCoreObjCWebFontCache
+
+#else // !PLATFORM(DARWIN)
+
 // Don't define SKIA on Mac. Undefine other things as well that might get set
 // as side-effects.
 #define WTF_PLATFORM_SKIA 1
 #undef WTF_PLATFORM_CG
 #undef WTF_PLATFORM_CF
-#endif
+
+#endif // !PLATFORM(DARWIN)
 
 #if !defined(WTF_USE_V8)
 #define WTF_USE_V8 1
 #endif
 
 #undef WTF_USE_CFNETWORK
 // Upstream Platform.h's #ifdef check for other graphics libraries doesn't
 // check SKIA, so it falls back on defining CAIRO.  Undo that here.
 // TODO(evanm): clean this up.
 #undef WTF_PLATFORM_CAIRO
@@ skipping 26 matching lines @@
 #define WTF_USE_SAFARI_THEME 1
 #endif
 
 #ifndef WEBCORE_NAVIGATOR_VENDOR
 #ifdef GOOGLE_CHROME_BUILD
 #define WEBCORE_NAVIGATOR_VENDOR "Google Inc."
 #else
 #define WEBCORE_NAVIGATOR_VENDOR ""
 #endif // ifdef GOOGLE_CHROME_BUILD
 #endif // ifndef WEBCORE_NAVIGATOR_VENDOR